As stated in the October 1989 issue of AGD Impact at page 4, "Dry mouth is unexplored territory for dentists, yet it haunts about one-third of all adult patients." Dry mouth may produce "pain, a burning sensation of the tongue, difficulty chewing and swallowing foods, . . . "
Two U.S. patents directed to the problem of dry mouth are U.S. Pat. Nos. 4,838,882 and 3,991,471. The former patent provides a pad or sponge contained in a knit cotton cloth that is saturated with water and placed in a cheek pouch of the user. Such an arrangement puffs out the cheek, is uncomfortable, unsanitary and liquid flow is not readily controlled. Further, such a pouch will interfere with chewing and, thus, must be removed while eating.
The latter patent provides a palatal appliance for maintaining humidity in the mouth and respiratory tract. It comprises a rigid plastic shell that conforms to the hard palate and holds a sponge saturated with liquid. Again, the discharge of liquid from the device is substantially uncontrolled and the device must be removed during eating.